A systematic comparative approach has been taken to provide the basis for a theoretical understanding of the function of taste. The investigations involve diverse species and the coordination of biochemical, behavioral, neural and nutritional techniques. The individual and species variation in taste preference as it relates to function is being studied. The physiological basis for this behavior will be further investigated. The role of environment in modifying taste behavior will be considered. Projects on the effects of undernutrition, i.e., vitamin, protein and mineral deficiencies, as well as malnutrition, on taste preference and threshold will be pursued. The role of the oropharyngeal area as a chemoreceptor is studied, particularly as it influences digestive secretions and other digestive functions.